Bladeless cleavers having a flexible tongue and related methods for cleaving an optical fiber using an abrasive medium

ABSTRACT

Methods, cleavers, and packagings for cleaving an optical fiber using an abrasive medium are disclosed. In one embodiment, the bladeless cleaver includes a body having a flexible tongue configured to receive an optical fiber. The flexible tongue is further configured to provide an arcuate surface to bend a portion of the optical fiber. The bladeless cleaver in this embodiment also includes a cleaver structure attached to the body that comprises an abrasive medium carrier configured to support an abrasive medium. The abrasive medium carrier is configured to be actuated to place the abrasive medium in contact with the portion of the optical fiber to create a flaw in the portion of the optical fiber.

RELATED APPLICATIONS

This application is related to U.S. patent application Ser. No.12/697,604, filed on Feb. 1, 2010, entitled “METHODS, CLEAVERS, ANDPACKAGINGS FOR CLEAVING AN OPTICAL FIBER USING AN ABRASIVE MEDIUM,” andU.S. patent application Ser. No. 12/710,746, filed on even dateherewith, entitled “BLADELESS CLEAVERS HAVING AN ARCUATE EXTERIORSURFACE AND RELATED METHODS FOR CLEAVING AN OPTICAL FIBER USING ANABRASIVE MEDIUM,” both of which are incorporated herein by reference intheir entireties.

BACKGROUND

1. Field of the Disclosure

The technology of the disclosure relates to cleaving optical fibers toprovide an end face on the optical fibers for fiber optic terminationpreparations.

2. Technical Background

Optical fibers can be used to transmit or process light in a variety ofapplications. Benefits of optical fiber include extremely wide bandwidthand low noise operation. Because of the advantages, optical fiber isincreasingly being used for a variety of applications, including but notlimited to broadband voice, video, and data transmission. Fiber opticnetworks employing optical fiber are being developed and used to delivervoice, video, and data transmissions to subscribers over both privateand public networks. These fiber optic networks often include separatedconnection points linking optical fibers to provide “live fiber” fromone connection point to another connection point. In this regard, fiberoptic equipment is located in data distribution centers or centraloffices to support interconnections.

Optical communication networks involve termination preparations toestablish connections between disparate optical fibers. For example,optical fibers can be spliced together to establish an opticalconnection. Optical fibers can also be connectorized with fiber opticconnectors that can be plugged together to establish an opticalconnection. In either case, it may be necessary for a technician toestablish the optical connection in the field. The technician cleavesthe optical fiber to prepare an end face on the optical fiber. Thetechnician may employ a cleaver that includes a blade to score, scribe,or otherwise induce a flaw in the glass of the optical fiber. Inducing aflaw in the glass of an optical fiber precedes breaking the glass at theflaw to produce an end face. The blade may either by pressed into theglass or swiped across the glass to induce the flaw. The end face canthen either be spliced to another optical fiber or connectorized with afiber optic connector to establish an optical connection.

Conventional cleaver blades are expensive. Conventional cleaver bladesmay employ an expensive hardened material(s), including diamond,sapphire, ruby, ceramics, steel, and carbide, as examples. Further, theconventional cleaver blade needs to include an extremely sharp edge tominimize the size of the flaw induced in the glass to reduce risk ofdamaging the core of the optical fiber to provide efficient lighttransfer. Providing a sharp edge on the conventional cleaver blade addscost. Inducing a large flaw in the glass may create a poor end face.Maintenance must be provided to keep the conventional cleaver bladesharp.

SUMMARY OF THE DETAILED DESCRIPTION

Embodiments disclosed in the detailed description include methods,cleavers, and packagings for cleaving an optical fiber using an abrasivemedium. The abrasive medium may be placed into contact with a portion ofan optical fiber to induce a flaw in the portion of the optical fiber.The optical fiber is broken about the induced flaw to create an end facefor fiber optic termination preparations. Cleaving the optical fiberprepares an end face on the optical fiber to prepare fiber opticterminations, including in the field. In this manner, the cost of thecleaver may be reduced by employing the abrasive medium. The abrasivemedium may be sufficiently inexpensive to be disposable as opposed tomaintaining a conventional cleaver blade. The abrasive medium may alsobe disposed on a flexible carrier that allows the abrasive medium to beemployed in flexible manners and cleaver form factors and/or packagings.

In this regard, in one embodiment, an alternative bladeless cleaver forcleaving an optical fiber is disclosed. The bladeless cleaver in thisembodiment includes a body having a flexible tongue configured toreceive an optical fiber. The flexible tongue is further configured toprovide an arcuate surface to bend a portion of the optical fiber. Thebladeless cleaver in this embodiment also includes a cleaver structureattached to the body that comprises an abrasive medium carrierconfigured to support an abrasive medium. The abrasive medium carrier isconfigured to be actuated to place the abrasive medium in contact withthe portion of the optical fiber to create a flaw in the portion of theoptical fiber.

In a method described herein, the bladeless cleaver of this embodimentmay be used to cleave an optical fiber without employing a conventionalblade. The method for cleaving an optical fiber without employing aconventional blade includes providing an optical fiber on a flexibletongue extending from a body of the bladeless cleaver. The method alsoincludes bending the flexible tongue to bend a portion of the opticalfiber and apply a tension to the portion of the optical fiber. A flaw isthen created in the portion of the optical fiber by actuating anabrasive medium carrier attached to the body to place an abrasive mediumdisposed in the abrasive medium carrier in contact with the portion ofthe optical fiber to create the flaw in the portion of the opticalfiber. After the flaw is created, the optical fiber is broken at theflaw to create a cleaved end face on the optical fiber.

Additional features and advantages will be set forth in the detaileddescription which follows, and in part will be readily apparent to thoseskilled in the art from that description or recognized by practicing theembodiments as described herein, including the detailed description thatfollows, the claims, as well as the appended drawings.

It is to be understood that both the foregoing general description andthe following detailed description present embodiments, and are intendedto provide an overview or framework for understanding the nature andcharacter of the disclosure. The accompanying drawings are included toprovide a further understanding, and are incorporated into andconstitute a part of this specification. The drawings illustrate variousembodiments, and together with the description serve to explain theprinciples and operation of the concepts disclosed.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is an exemplary method for cleaving an optical fiber by creatinga flaw in a portion of the optical fiber using an abrasive medium;

FIG. 2 schematically illustrates an exemplary end face of the opticalfiber of FIG. 1 after being cleaved using the abrasive medium in FIG. 1;

FIG. 3 is a side view of an exemplary bladeless cleaver configured toplace an abrasive medium in contact with a portion of the optical fiberto create a flaw in the portion of the optical fiber;

FIG. 4 is a side view of the bladeless cleaver of FIG. 3 with a portionof an optical fiber inserted into a fiber stripper disposed in thebladeless cleaver and disposed along a guide surface of the bladelesscleaver;

FIG. 5 is a left perspective view of the body of the bladeless cleaverof FIG. 3 illustrating a fiber stripper disposed in a track disposedalong the guide surface of the bladeless cleaver to allow the fiberstripper to be translated about the guide surface to strip coating fromthe portion of the optical fiber;

FIG. 6 is a left view of the bladeless cleaver of FIG. 3 prior toinsertion of an optical fiber into a clamp of the fiber stripper;

FIG. 7 is a left view of the bladeless cleaver of FIG. 3 after insertionof an optical fiber into the fiber stripper and the clamp of the fiberstripper closed;

FIG. 8 is a top view of the bladeless cleaver and optical fiberillustrated in FIG. 7;

FIG. 9 is a top view of the bladeless cleaver of FIGS. 7 and 8 with thefiber stripper translated about the guide surface to strip the opticalfiber clamped by the fiber stripper;

FIG. 10 is a top view of the bladeless cleaver of FIG. 9 with a cleaverstructure supporting an abrasive medium actuated to place the abrasivemedium in contact with a stripped portion of the optical fiber to createa flaw in the stripped portion of the optical fiber;

FIG. 11 is a front perspective view of the bladeless cleaver of FIG. 3disposed in a compartment of a fiber optic package;

FIG. 12 is a left perspective view of the fiber optic package of FIG. 11illustrating an opening disposed through the fiber optic package alignedwith a guide surface disposed in the bladeless cleaver and configured toreceive a portion of an optical fiber and direct the portion of theoptical fiber along the guide surface;

FIG. 13 is a top view of the fiber optic package of FIG. 11 with anoptical fiber inserted through the opening of the fiber optic packageand the fiber stripper and disposed along the guide surface of thebladeless cleaver;

FIG. 14 is a top view of the fiber optic package of FIG. 11 with thefiber stripper of the bladeless cleaver translated about the guidesurface to strip the optical fiber clamped by the fiber stripper;

FIG. 15 is a side view of an alternate embodiment of an exemplarybladeless cleaver configured to place an abrasive medium in contact witha portion of the optical fiber to create a flaw in the portion of theoptical fiber;

FIG. 16 is a side view of the bladeless cleaver of FIG. 15, where a tabof a flexible tongue of the bladeless cleaver is locked into a slot ofthe body of the bladeless cleaver such that the bladeless cleaver isready for cleaving an optical fiber;

FIG. 17 shows a schematic representation (not to scale) of a refractiveindex profile of a cross-section of the glass portion of an exemplaryembodiment of a multimode optical fiber disclosed herein wherein adepressed-index annular portion is offset from a core and is surroundedby an outer annular portion; and

FIG. 18 is a schematic representation (not to scale) of across-sectional view of the multimode optical fiber of FIG. 17.

DETAILED DESCRIPTION

Reference will now be made in detail to the embodiments, examples ofwhich are illustrated in the accompanying drawings, in which some, butnot all embodiments are shown. Indeed, the concepts may be embodied inmany different forms and should not be construed as limiting herein;rather, these embodiments are provided so that this disclosure willsatisfy applicable legal requirements. Whenever possible, like referencenumbers will be used to refer to like components or parts.

Embodiments disclosed in the detailed description include methods,cleavers, and packagings for cleaving an optical fiber using an abrasivemedium. The abrasive medium may be placed into contact with a portion ofan optical fiber to induce a flaw in the portion of the optical fiber.The optical fiber is broken about the induced flaw to create an end facefor fiber optic termination preparations. Cleaving the optical fiberprepares an end face on the optical fiber to prepare fiber opticterminations, including in the field.

An abrasive medium for cleaving an optical fiber is more economical thana conventional cleaver blade. An abrasive medium for cleaving an opticalfiber may cost on the order of cents, whereas conventional cleaverblades can cost tens of dollars up to a hundred dollars as an example.By employing a less expensive abrasive medium, costs associated withmaintaining a sharp edge on a conventional cleaver blade to avoidinducing a large flaw in an optical fiber are avoided. Consequently,with the cleavers and methods disclosed, it is financially feasible todispose and replace a used abrasive medium in the cleaver with a newabrasive medium after a few uses. For example, the abrasive medium maybe disposed and replaced after ten (10) to twenty (20) cleaves. Use ofan abrasive medium to cleave an optical fiber may also allow smallerform factors of optical fiber cleavers over use of conventional cleaverblades. The abrasive medium may be disposed on a rigid or flexiblemember. If the abrasive medium is disposed on a flexible member, theabrasive medium may be easily disposed and replaceable in a variety ofcleaver form factors, thus making these form factors feasible for use bytechnicians to cleave optical fibers.

In this regard, FIG. 1 is an exemplary method for cleaving an opticalfiber by creating or inducing a flaw in a portion of the optical fiberusing an abrasive medium. As illustrated therein, an optical fiber 10 isprovided. The optical fiber 10 can be any type of optical fiber,including but not limited to a single-mode optical fiber and amulti-mode optical fiber. The optical fiber 10 may be of any sizediameter D₁, as illustrated in FIG. 2. The optical fiber 10 may includea core 12 surrounded by cladding 14 to provide total internal reflection(TIR) of light 16 propagated down the core 12, as illustrated in FIG. 2.The cladding 14 may be provided as glass or other material, includingbut not limited to a polymer cladding such as a plastic clad silica asan example. An outer coating (not shown) may be disposed around thecladding 14. The optical fiber 10 may be provided as part of a singlefiber or multi-fiber fiber optic cable.

When splicing or connectorizing the optical fiber 10, it is necessary toprovide an end face 18 on the optical fiber 10, as schematicallyillustrated in FIG. 2. The end face 18 is aligned with an end face ofanother optical fiber to transfer the light 16 from the optical fiber 10to the spliced or connected optical fiber. When splicing orconnectorizing an optical fiber, it is important to provide an end face18 that has a relatively smooth and mirror-like surface to achieve anefficient light transfer. It is also important to avoid damaging thecore 12 and/or the cladding 14 of the optical fiber 10. In this regard,the optical fiber 10 is cleaved to prepare the end face 18. The end face18 is prepared by introducing a flaw into a portion of the optical fiber10. The end face 18 is formed when the optical fiber 10 is broken aboutthe induced flaw.

In this regard, instead of employing a conventional blade to cleave theoptical fiber, an abrasive medium 20 is employed, as illustrated inFIG. 1. The abrasive medium 20 is an abrasive material. The abrasivemedium 20 is disposed on a carrier 22 in this embodiment. The carrier 22is controlled to bring the abrasive medium 20 in contact with a portion24 of the optical fiber 10, as illustrated in FIG. 1, to induce a flaw26 in the portion 24 of the optical fiber 10. The flaw 26 cracks theportion 24 of the optical fiber 10. The end face 18 is created in theportion 24 of the optical fiber 10 by breaking the optical fiber 10 atthe flaw 26. In this manner, the abrasive medium 20 cleaves the opticalfiber 10.

The abrasive medium 20 is not a conventional blade in this embodiment. Aconventional blade is typically a hardened material that has a sharpedge. The abrasive medium 20 does not have a sharp edge. A conventionalblade has a smooth surface, wherein the abrasive medium 20 does not havea smooth surface. Simply stated, the abrasive medium 20 does not includea sharp blade that can easily be placed into precise contact with anoptical fiber like the conventional blade. Thus, the cleaving of theoptical fiber 10 in FIG. 1 using the abrasive medium 20 is a bladelessform and method of cleaving the optical fiber 10.

The carrier 22 may be controlled by human hand or a cleaving device,examples of which will be described below in this disclosure, to placethe abrasive medium 20 in contact with the optical fiber 10 to inducethe flaw 26 in the optical fiber 10. In the embodiment of FIG. 1, theoptical fiber 10 is held in place while the carrier 22 is moved in adirection D₂ towards the portion 24 of the optical fiber 10 to bring theabrasive medium 20 in contact with the portion 24 of the optical fiber10. The carrier 22 may be controlled in a swiping motion for example.Alternatively, the carrier 22 could be held in place and the portion 24of the optical fiber 10 moved to be brought into contact with theabrasive medium 20. In either case, relative movement is created betweenthe portion 24 of the optical fiber 10 and the abrasive medium 20 tocreate the flaw 26.

Any coating (not shown) disposed on the outside of the optical fiber 10is removed prior to placing the abrasive medium 20 in contact with theoptical fiber 10 so that the abrasive medium 20 directly contacts glassof the optical fiber 10. In this regard, any coating disposed around thecore 12 and/or the cladding 14 may be removed prior to placing theabrasive medium 20 in contact with the optical fiber 10.

The abrasive medium 20 may be material provided in grit form on thecarrier 22. The abrasive medium 20 may be provided by any type ofmaterial or combination or compound of elements or materials.Non-limiting examples of the abrasive medium 20 include, but are notlimited to diamond, silicon carbide, aluminum oxide, silicon dioxide,cerium oxide, and ferrous oxide. The size of the abrasive medium 20 maybe any suitable size. As an example only, the size of the abrasivemedium 20 may be between five (5) and twenty (20) micrometers (μm) as anon-limiting example. For example, the abrasive medium 20 may be fifteen(15) μm diamond, or eight (8) μm carbide, as non-limiting examples.

The carrier 22 may be any material that is configured to support theabrasive medium 20 disposed or deposited thereon. For example, thecarrier 22 may be a film, such as a polishing film. The abrasive medium20 is disposed on a surface of the carrier 22. The abrasive medium 20may be disposed or deposited on the entire surface area of the carrier22 or only a portion of the surface area of the carrier 22. For example,the abrasive medium 20 may be disposed on an edge of the carrier 22.Other non-limiting examples of carriers, include, but are not limited toa wire, a string, a block, and a body. The carrier 22 may be of any sizeand made from any type of material desired, including but not limited toa polymer, plastic, and metal, as non-limiting examples. The quality andnature of the abrasive medium 20 and the carrier 22 determine the lifeor number of uses to cleave the optical fiber 10.

The carrier 22 may be rigid or flexible. In the embodiment illustratedin FIG. 1, the carrier 22 is flexible. Providing a flexible carrier 22allows a precise portion of the abrasive medium 20 disposed or depositedthereon to be placed into contact with the optical fiber 10 to inducethe flaw 26 in the portion 24 of the optical fiber 10 in FIG. 1 in thisembodiment. Providing a flexible carrier 22 may also allow the deployingof the abrasive medium 20 in cleavers and other packagings that may notbe possible or convenient if a conventional blade cleaver were employed.Examples of such cleavers and packagings are discussed in more detailbelow with regard to FIGS. 3-14.

The optical fiber 10 may be placed under stress prior to placing theabrasive medium 20 in contact with the optical fiber 10 to cleave thesame. Placing the optical fiber 10 under stress prevents the portion 24of the optical fiber 10 from moving when contacted by the abrasivemedium 20. Placing the optical fiber 10 under stress prior to inducingthe flaw 26 in the optical fiber 10 with the abrasive medium 20 alsopropagates the induced flaw 26 to cleave the optical fiber 10. Examplesof placing the optical fiber 10 under stress includes but is not limitedto placing a tension on the optical fiber 10, rotating or twisting theoptical fiber 10, or bending the optical fiber 10.

For example, the optical fiber 10 in FIG. 1 is placed under tensionprior to the abrasive medium 20 being placed into contact with theportion 24 of the optical fiber 10. As illustrated in FIG. 1, portions28A, 28B of the optical fiber 10 disposed on each side of the portion 24of the optical fiber 10 where the flaw 26 is desired to be induced areclamped by clamps 30A, 30B. The clamps 30A, 30B with the portions 28A,28B of the optical fiber 10 secured therein may be pulled away from eachother in directions D₃ and D₄ to place the portion 24 of the opticalfiber 10 under tension. Thus, once the flaw 26 is introduced by theabrasive medium 20 in the portion 24 of the optical fiber 10, thetension will cause the portion 24 of the optical fiber 10 to break aboutthe flaw 26 to create the end face 18. If the portion 24 of the opticalfiber 10 is not placed under a stress when the flaw 26 is introduced bythe abrasive medium 20, a stress could be subsequently placed on theportion 24 of the optical fiber 10 to create the break about the flaw 26to create the end face 18.

It may also be desirable to bend the portion 24 of the optical fiber 10in addition to placing the portion 24 of the optical fiber 10 under atension or other stress prior to inducing the flaw 26 with the abrasivemedium 20. Placing a bend in the portion 24 of the optical fiber 10assists in propagating the flaw 26 into a break in the portion 24 of theoptical fiber 10 to create the end face 18. Placing a bend in theportion 24 of the optical fiber 10 creates tension on the outsidesurface of a bent portion of the optical fiber 10, which assists inpropagating the flaw 26 into a break in the portion 24 of the opticalfiber 10.

After the portion 24 of the optical fiber 10 is broken at the flaw 26,the end face 18 is created, as illustrated by example in FIG. 2. The endface 18 illustrated in FIG. 2 is disposed in the portion 24 of theoptical fiber 10 in a cross-sectional plane P₁ orthogonal orsubstantially orthogonal to a longitudinal axis A₁ of the optical fiber10. However, the abrasive medium 20 could also be used to provide anangle-cleaved end face in the portion 24 of the optical fiber 10, ifdesired. For example, the portion 24 of the optical fiber 10 could berotated during the introduction of the flaw 26 with the abrasive medium20 to affect the angle of the end face created in the portion 24 of theoptical fiber 10. The apex of the bend disposed in the portion 24 of theoptical fiber 10 when the abrasive medium 20 is used to induce the flaw26 can also affect the angle of the end face created in the portion 24of the optical fiber 10. Methods of creating an angled-end face using aconventional cleaver blade can be used to create an angled end faceusing the abrasive medium 20.

The remainder of this disclosure includes exemplary methods, cleavers,and packagings that employ an abrasive medium to cleave an opticalfiber. The methods and principles discussed above and with respect toFIGS. 1 and 2 may be employed in these methods, cleavers, andpackagings. In this regard, FIG. 3 is a side view of an exemplarybladeless cleaver 40 that is configured to support an abrasive mediumthat is placed in contact with a portion of an optical fiber to cleavethe optical fiber. As will be discussed in more detail below with regardto FIGS. 3-10, the bladeless cleaver 40 is designed to allow atechnician to engage a portion of an optical fiber to be cleaved, toplace a bend in the portion of the optical fiber, to clamp and strip theportion of the optical fiber, and place a supported abrasive material incontact with the portion of the optical fiber to create a flaw in theportion of the optical fiber.

As illustrated in FIG. 3, the bladeless cleaver 40 includes a body 42.The body 42 supports other components of the bladeless cleaver 40 aswill be described below. The body 42 contains a guide surface 44 toguide a portion 46 of an optical fiber 48 to be cleaved, as illustratedin FIG. 4. The optical fiber 48 may have any of the attributes of theoptical fiber 10 discussed above with regard to FIGS. 1 and 2, as anexample. In this embodiment, the guide surface 44 is an arcuate surfaceof radius R₁ for placing a bend in the portion 46 of the optical fiber48 prior to cleaving the portion 46 of the optical fiber 48. However,the guide surface 44 is not required to be an arcuate surface. If theguide surface 44 is arcuate, the guide surface 44 may be of any radiusdesired.

A cleaver structure 50 is attached to the body 42 and contains anabrasive medium structure 52 configured to support an abrasive medium54, as illustrated in FIGS. 6 and 8. As will be described in more detailbelow, the cleaver structure 50 is configured to be actuated to placethe abrasive medium 54 in contact with the portion 46 of the opticalfiber 48 to create a flaw in the portion 46 of the optical fiber 48. Theabrasive medium 54 may have any of the characteristics of the abrasivemedium 20 discussed above with regard to FIGS. 1 and 2. Further, theabrasive medium 54 may be disposed on a carrier 56, as illustrated inFIGS. 6 and 8. The carrier 56 may have any of the characteristics of thecarrier 22 discussed above with regard to FIGS. 1 and 2.

A fiber stripper 60 is optionally attached to the body 42 in thisembodiment to strip coating from the portion 46 of the optical fiber 48disposed about the guide surface 44 of the body 42. The fiber stripper60 is used to strip coating from the portion 46 of the optical fiber 48prior to the cleaver structure 50 placing the abrasive medium 54 incontact with the portion 46 of the optical fiber 48. When the portion 46of the optical fiber 48 is initially disposed about the guide surface 44of the body 42, the fiber stripper 60 is disposed at a first end 62 ofthe guide surface 44, as illustrated in FIG. 3. The portion 46 of theoptical fiber 48 may then be disposed around the entire guide surface 44until the portion 46 of the optical fiber 48 reaches a second end 64 ofthe guide surface 44, as also illustrated in FIG. 3. Thereafter, thefiber stripper 60 may be aligned and secured to the portion 46 of theoptical fiber 48 to prepare the same for stripping. In other words, theoptical fiber 48 is inserted onto fiber stripper 60 so that an end ofthe optical fiber 48 extends a suitable distance therein, such as tosecond end 64 when the fiber stripper 60 is disposed on the first end 62of the guide surface 44. Thereafter, the fiber stripper 60 can then betranslated when secured to the portion 46 of the optical fiber 48circumferentially around the guide surface 44, noted as C₁ in FIG. 4,until the fiber striper 60 is disposed at the second end 64 of the guidesurface 44, as illustrated in FIG. 4. As the fiber stripper 60 istranslated, any coating disposed on the portion 46 of the optical fiber48 is removed by fiber stripper 60.

By way of example, FIG. 5 illustrates the translation of the fiberstripper 60 circumferentially about the guide surface 44 to strip theportion 46 of the optical fiber 48. In this embodiment, a guide or track66 is disposed in the body 42 of the bladeless cleaver 40 adjacent theguide surface 44. The track 66 is disposed around the radius R₁ of theguide surface 44 in this embodiment. The track 66 retains the fiberstripper 60 and allows the fiber stripper 60 to be secured to the body42 as the fiber stripper 60 is translated circumferentially about theguide surface 44. This is further illustrated in FIG. 6 illustrating aleft side view of the bladeless cleaver 40. As illustrated therein, thefiber stripper 60 is engaged to the track 66 in the body 42 at the firstend 62 of the guide surface 44. The fiber stripper 60 contains aprotrusion 68 that acts as a rail configured to engage with the track66, but other suitable guide structures are possible.

The fiber stripper 60 in this embodiment also contains a clamp 70 tosecure the fiber stripper 60 to the portion 46 of the optical fiber 48prior to stripping in this embodiment, as illustrated in FIG. 6. In thisembodiment, the clamp 70 is disposed in the fiber stripper 60, but suchis not required. The clamp 70 illustrated in FIG. 6 is open to receivethe portion 46 of the optical fiber 48. When the clamp 70 is open, theclamp 70 disposed in the fiber stripper 60 contains an opening 72configured to receive the portion 46 of the optical fiber 48 whendisposed therein. The portion 46 of the optical fiber 48 is insertedthrough the opening 72 when disposing the portion 46 of the opticalfiber 48 around the guide surface 44 of the bladeless cleaver 40 (seealso, FIG. 4). To secure the fiber stripper 60 to the portion 46 of theoptical fiber 48, the clamp 70 is closed onto the portion 46 of theoptical fiber 48 when the fiber stripper 60 is disposed at the first end62 of the guide surface 44, as illustrated in the left side and topviews of the bladeless cleaver 40 in FIGS. 7 and 8, respectively. Whenthe clamp 70 is closed, the size of the opening 72 is reduced from whenthe clamp 70 is opened, as illustrated in FIG. 6, to secure the fiberstripper 60 to the portion 46 of the optical fiber 48. The opening 72when the clamp 70 is closed is designed to be sized such that anycoating on the portion 46 of the optical fiber 48 is removed when thefiber stripper 60 is translated circumferentially about the guidesurface 44 to the second end 64 without damaging the glass of theoptical fiber 48, as illustrated in the top view of the bladelesscleaver 40 in FIG. 9. The clamp 70 may also place a stress on theportion 46 of the optical fiber 48 prior to cleaving.

As discussed above and illustrated in FIGS. 3 and 4, the bladelesscleaver 40 includes the cleaver structure 50 attached to the body 42 tosupport the carrier 56 having the abrasive medium 54 disposed thereon.The cleaver structure 50 controls placing the abrasive medium 54 incontact with the portion 46 of the optical fiber 48 to induce a flawtherein, as described below. As illustrated in FIGS. 5 and 6, the body42 contains openings 74 that are configured to support attachment of thecleaver structure 50 to the body 42. As illustrated in FIG. 6, twoshafts 76, one hidden by the carrier 56 and one unobstructed, aredisposed in the cleaver structure 50 to space apart the cleaverstructure 50 from the body 42 when the cleaver structure 50 is attachedto the body 42. The shafts 76 are disposed through the openings 74 inthe body 42. Springs (not shown) are disposed inside the shafts 76,wherein the springs bottom out in blind holes 78 disposed on theopposite side of the body 42 from the openings 74. In this manner, thecleaver structure 50 is spring-actuated with the body 42.

The cleaver structure 50 can be actuated to be moved in a direction D₅towards the body 42 and guide surface 44, as illustrated in FIGS. 6 and8, by exerting a force on the cleaver structure 50 towards the body 42.The springs inside the shafts 76 are compressed as a result, and thecleaver structure 50 is moved against the body 42, as illustrated in thetop view of the bladeless cleaver 40 in FIG. 10. When the force exertedon the cleaver structure 50 is released, the springs in the shafts 76release their stored energy and the cleaver structure 50 is returned toits position in FIG. 6. Because the carrier 56 having the abrasivemedium 54 disposed thereon is disposed in the abrasive medium structure52 disposed in the cleaver structure 50, when the cleaver structure 50is moved towards the body 42, the cleaver structure 50 places theabrasive medium 54 into contact with the portion 46 of the optical fiber48 to induce a flaw in the portion 46 of the optical fiber 48. Due tothe stress induced into the portion 46 of the optical fiber 48 by theclamp 70 of the fiber stripper 60 as previously discussed andillustrated in FIG. 4, the portion 46 of the optical fiber 48 is cleaveddue to the bend disposed in the portion 46 of the optical fiber 48and/or the stress due to the clamping of the portion 46 of the opticalfiber 48 by the clamp 70.

To support the abrasive medium 54 in the cleaver structure 50, theabrasive medium structure 52 is disposed in the cleaver structure 50 inthis embodiment. The abrasive medium structure 52 supports the carrier56 containing the abrasive medium 54. Providing an abrasive mediumstructure 52 allows the abrasive medium 54 to be disposed within thebladeless cleaver 40 as opposed to having to be provided and handledseparately by a technician from a cleaver. Thus, the alignment andcontact of the abrasive medium 54 with the portion 46 of the opticalfiber 48 is controlled by the cleaver structure 50 for quality andrepeatability in cleaving.

In this embodiment, as illustrated in the top views of the bladelesscleaver 40 in FIGS. 8-10, the abrasive medium structure 52 is providedin the form of an abrasive medium compartment 80. The abrasive mediumcompartment 80 is an opening 81 in this embodiment that is configured toallow the carrier 56 containing the abrasive medium 54 to be disposedtherein. FIGS. 6 and 7 illustrated the carrier 56 inserted into theabrasive medium compartment 80 from a side view. The opening 81 does notextend all the way through the cleaver structure 50. Alternatively, theopening 81 could extend all the way through the cleaver structure 50. Inthis embodiment, the abrasive medium compartment 80 is disposed at anangle with respect to a tangent plane of the guide surface 44, althoughany orientation desired can be provided for the abrasive mediumcompartment 80 in the cleaver structure 50.

A technician can insert the carrier 56 containing the abrasive medium 54prior to cleaving. The carrier 56 inserted into the abrasive mediumcompartment 80 extends beyond the opening 81 in the abrasive mediumcompartment 80 on a left side 82 of the cleaver structure 50 in thisembodiment, as illustrated in FIGS. 8-10. The carrier 56 is designed andsized such that the abrasive medium 54 disposed thereon does not comeinto contact with the portion 46 of the optical fiber 48 disposed alongthe guide surface 44 when a force is not exerted against the carrierstructure 50, as illustrated in FIGS. 8 and 9. However, when a force isexerted on the carrier structure 50, the sizing of the carrier 56disposed in the abrasive medium compartment 80 is such that the abrasivemedium 54 disposed on the carrier 56 comes into contact with the portion46 of the optical fiber 48, thereby inducting a flaw, as illustrated inFIG. 10.

The bladeless cleaver 40 described above may be used by a technician tocleave an optical fiber to prepare an end face in the field to prepare atermination. For example, the termination may be prepared for splicingthe optical fiber to another optical fiber or connectorizing the opticalfiber. Preparing the termination may also include employing othercomponents, such as connectors, crimp rings, boots, and other tools, asexamples. In this regard, a fiber optic package 90 may be provided likeillustrated in FIG. 11 as a convenient manner to store these componentsfor easy transport and access by a technician. The fiber optic package90 includes an enclosure 92 having a plurality of bins or compartments94 for storing components used by the technician. A cover 96 may beattached to the enclosure 92 to close off access to the compartments 94to protect the components stored therein. The bladeless cleaver 40 mayalso be stored in a compartment 94 of the fiber optic package 90, asillustrated in FIG. 11, as a convenient means to include a cleaver withthe fiber optic package 90 containing other fiber optic components usedto prepare and complete an optical fiber termination. Alternatively, abladed cleaver may be stored in the compartment 94 of the fiber opticpackage 90.

For additional convenience, the fiber optic package 90 is configured toallow a technician to cleave an optical fiber without having to removethe bladeless cleaver 40 from the fiber optic package 90. In thisregard, an opening 97 is disposed through the enclosure 92, asillustrated in FIG. 12. The opening 97 is disposed through the enclosure92 to provide access to the compartment 94 containing the bladelesscleaver 40. The opening 97 in this embodiment is aligned with the firstend 62 of the guide surface 44 of the bladeless cleaver 40. In thismanner, when it is desired to cleave an optical fiber using thebladeless cleaver 40 disposed in the fiber optic package 90, the portion46 of the optical fiber 48 is disposed through the opening 97 in theenclosure 92, as illustrated in FIG. 13. Because the opening 97 isaligned with the first end 62 of the guide surface 44, inserting theportion 46 of the optical fiber 48 through the opening 97 inserts theportion 46 of the optical fiber 48 through the fiber stripper 60. Thebladeless cleaver 40 need not be removed from the fiber optic package90. The portion 46 of the optical fiber 48 can be continued to be pushedthrough the opening 72 wherein the portion 46 is disposed along theguide surface 44 of the body 42, as previously described. The portion 46of the optical fiber 48 can be continued to be disposed along the guidesurface 44 until the portion 46 of the optical fiber 48 reaches a fiberstop 98, which in this embodiment is an interior wall 99 of thecompartment 94 containing the bladeless cleaver 40, as illustrated inFIG. 13.

Thereafter, the clamp 70 disposed in the fiber stripper 60 can beclosed, as previously described. The portion 46 of the optical fiber 48is then ready for stripping. In this regard and as previously described,the fiber stripper 60 can be translated about the guide surface 44 tostrip coating from the portion 46 of the optical fiber 48. FIG. 14illustrates the fiber stripper 60 translated to the second end 64 of theguide surface 44 adjacent to the fiber stop 98. The portion 46 of theoptical fiber 48 can now be cleaved. In this manner, as previouslydiscussed, a force can be exerted downward on the cleaver structure 50,as illustrated in FIG. 14, to cleave the portion 46 of the optical fiber48. As previously discussed with regard to FIG. 10, exerting a force topush the cleaver structure 50 into the body 42 causes the abrasivemedium 54 disposed on the carrier 56 disposed in the abrasive mediumcompartment 80 to come into contact with the portion 46 of the opticalfiber 48. A flaw is introduced into the portion 46 of the optical fiber48 as a result, thereby allowing the portion 46 of the optical fiber 48to be broken about the flaw to create an end face in portion 46 of theoptical fiber 48. The methods described above with regard to creating aflaw in an optical fiber employing the bladeless cleaver 40 to cleave anoptical fiber may be employed when the bladeless cleaver 40 is disposedin the fiber optic package 90.

For convenience, the cleaver referenced above with regard to FIGS. 11-14as being included in the compartment 94 of the fiber optic package 90 isthe bladeless cleaver 40 of FIGS. 3-10. However, it is to be understoodthat any other cleaver, including a conventional bladed cleaver, may beincluded in the compartment 94 of the fiber optic package 90 in FIGS.11-14. Such bladed cleaver can include a body, a guide surface disposedin the body to guide a portion of an optical fiber, and a cleaverstructure attached to the body and comprising an abrasive mediumstructure configured to support an abrasive medium, wherein the cleaverstructure further comprises an actuator configured to actuate withrespect to the body to place the abrasive medium in contact with theportion of the optical fiber to create a flaw in the portion of theoptical fiber.

Other embodiments of bladeless cleavers designed to allow a technicianto engage a portion of an optical fiber to be cleaved, to place a bendin the portion of the optical fiber, and place an abrasive material incontact with the portion of the optical fiber to create a flaw in theportion of the optical fiber are possible.

FIG. 15 is a side view of another exemplary bladeless cleaver 100. Thebladeless cleaver 100 is also configured to support an abrasive mediumthat is placed in contact with a portion of an optical fiber to cleavethe optical fiber. Although the method of use of the bladeless cleaver100 of FIG. 15 is described in more detail below, in general, thebladeless cleaver 100 of FIG. 15 may be used to cleave an optical fiberwithout employing a conventional blade by providing an optical fiber onthe flexible tongue and bending the flexible tongue such that it bends aportion of the optical fiber and applies a tension to the optical fiber.A flaw may then be created in a portion of the optical fiber byactuating the abrasive medium carrier attached to the body to place theabrasive medium in contact with the portion of the optical fiber tocreate a flaw in the portion of the optical fiber. The optical fiber maythen be broken at the flaw to create a cleaved end face on the opticalfiber.

In this regard, as illustrated in FIG. 15, the bladeless cleaver 100includes a body 102 in this embodiment. The body 102 supports othercomponents of the bladeless cleaver 100 as will be described below. Thebody 102 comprises a finger hole 104 through which a technician mayplace one or more fingers (or thumb) in order to be able to securelyhandle the bladeless cleaver 100 during use. The body 102 comprises aflexible tongue 106 that extends from the body 102. In the embodimentshown in FIG. 15, the flexible tongue 106 is an integrated portion ofthe body 102. In another embodiment, the flexible tongue 106 may be aseparate piece that is attached to the body 102 by any known manner. Theflexible tongue 106 has a fiber guide surface 107 and a distal end 108.The flexible tongue 106 is configured to provide the fiber guide surface107 to bend a portion of an optical fiber to be cleaved. In oneembodiment, a hinge 110 having an opening 112 extends from the distalend 108 of the flexible tongue 106. The hinge 110 may be a living hingein one embodiment. A notch 114 may be located at or near the distal end108 of the flexible tongue 106, where the opening 112 of hinge 110 isconfigured to fit over notch 114 when the hinge 110 is closed. A tab 116may be provided near a deformation 118 in the flexible tongue 106. Theflexible tongue 106 may then be bent such that a portion of the flexibletongue 106 closer to the distal end 108 bends at the deformation 118 andthe tab 116 may be placed into a slot 120 of the body 102.

As further illustrated in FIG. 15, a cleaver structure 121 is attachedto the body 102 and includes an abrasive medium carrier 122. As will bedescribed in more detail below, the cleaver structure 121, or theabrasive medium carrier 122 included therein, may be configured to beactuated to place the abrasive medium 126 in contact with a portion ofan optical fiber to create a flaw in the portion of the optical fiber.In one embodiment, the abrasive medium carrier 122 is comprised of abase portion 123 and a cover portion 124. The abrasive medium carrier122 is configured to support an abrasive medium 126 that is used tocreate a flaw in a portion of an optical fiber to cleave the opticalfiber. In one embodiment, the abrasive medium 126 may be in the form ofone or more tear away sheets of abrasive film that are held in place byabrasive medium holding members 128A and 128B. In other embodiments, theabrasive medium 126 may be similar to, and have any of thecharacteristics of, the abrasive medium 20 discussed above with regardto FIGS. 1 and 2. In addition, the abrasive medium 126 may be disposedon a carrier similar to carrier 56, as illustrated in FIGS. 6 and 8,where the carrier may have any of the characteristics of the carrier 22discussed above with regard to FIGS. 1 and 2.

In the embodiment shown in FIGS. 15 and 16, the cover portion 124 of theabrasive medium structure 122 may be closed to cover the abrasive medium126. In this manner, the cover portion 124 retains the abrasive medium126 in the abrasive medium carrier 122 and protects the abrasive medium126. Openings 130A and 130B in the cover portion 124 may fit onto intoabrasive medium holding members 128A and 128B such that the coverportion 124 stays closed and the abrasive medium carrier 122 with theabrasive medium 126 is retained in place. As will be described in moredetail below, the abrasive medium carrier 122 may be configured to beactuated to place the abrasive medium 126 in contact with a portion ofan optical fiber to create a flaw in the portion of the optical fiberfor cleaving the optical fiber.

The cleaver structure 121 may be attached to the body by any mannerknown to one of ordinary skill in the art. In the embodiment shown inFIG. 15, the cleaver structure 121 may comprise a locking mechanism 132having at least one compressible curved lip 134 configured to be placedinto a cleaver structure opening 136 located in the body 102 of thebladeless cleaver 100. The locking mechanism 132 serves to attach thecleaver structure 121 to the body 102 of the bladeless cleaver 100. Thelocking mechanism 132 may be compressed such that it fits through thecleaver structure opening 136 and when uncompressed, the at least onecompressible curved lip 134 fits against the body 102 such that thecleaver structure 121 is attached to the body 102.

The body 102 may also have a spring fiber guide 138 and a stop 140located at a proximal end 142 of the body 102. In the embodiment shownin FIG. 15, the spring fiber guide 138 and the stop 140 are formedtogether and attached as a separate piece to the body 102. The stop 140is used to stop an optical fiber placed on the flexible tongue 106 thatis allowed to follow the fiber guide surface 107 until a stripped end ofthe optical fiber (with exposed glass) makes contact with the stop 140.A spring (not shown) in the spring fiber guide 138 serves to allow atension to be placed on an optical fiber in contact with the stop 140when the flexible tongue 106 is bent. In other embodiments, the springfiber guide 138 and the stop 140 may be integrated into the body 102.The spring fiber guide 138 includes a spring (not shown) that holds thespring fiber guide 138 and stop 140 in place at the proximal end 142 ofthe body 102. An optical fiber may be placed along the fiber guidesurface 107 and moved toward the proximal end 142 until the opticalfiber makes contact with the stop 140.

FIG. 15 shows the bladeless cleaver 100 as it would be shipped to atechnician and prior to being used by a technician to engage a portionof an optical fiber to be cleaved, to place a bend in the portion of theoptical fiber, to clamp and strip the portion of the optical fiber, andplace a supported abrasive material in contact with the portion of theoptical fiber to create a flaw in the portion of the optical fiber. FIG.15 shows the bladeless cleaver 100 with the flexible tongue 106 in theunlocked position.

FIG. 16 shows the bladeless cleaver 100 as it is ready for cleaving anoptical fiber. The flexible tongue 106 contains a fiber guide surface107 to guide a portion 146 of an optical fiber 148 to be cleaved, asillustrated in FIG. 16. A portion 146 of the optical fiber 148 may bestripped of any coating disposed on the outside of the optical fiber 148by any conventional means prior to placing the optical fiber 148 ontothe flexible tongue 106. The optical fiber 148 may have any of theattributes of the optical fiber 10 or optical fiber 48 discussed abovewith regard to FIGS. 1, 2, and 4, as an example. As illustrated in FIG.16, the flexible tongue 106 has been bent such that the tab 116 issnapped into the slot 120 of the body 102 of the bladeless cleaver 100and the flexible tongue 106 is locked into place. The flexible tongue106 in the bent and locked position provides a bent radius of radius R₅for the optic fiber 148 to follow.

Looking at FIGS. 15 and 16 together, the method of operation of thebladeless cleaver 100 to create a flaw in the portion 146 of the opticalfiber 148 in order to create a cleaved end face on the optical fiber 148may be as follows. In the unlocked position as shown in FIG. 15, atechnician may place an optical fiber 148 onto the flexible tongue 106from the distal end 108 of the body 102 of bladeless cleaver 100. Anycoating disposed on the outside of the portion 146 of the optical fibermay be removed (stripped) prior to placing the optical fiber 148 ontothe flexible tongue 106 by any conventional stripper. The flexibletongue 106 contains a fiber guide surface 107 to guide the portion 146of an optical fiber 148 to be cleaved. The optical fiber 148 may beallowed to follow the fiber guide surface 107 until the portion 146 ofthe optical fiber 148 (with exposed glass) makes contact with the stop140. The fiber guide surface 107 may include a groove or channel (notshown) to help guide the optical fiber 148 and hold the optical fiber148 in place, although such a groove or channel is not required. Oncethe portion 146 of the optical fiber 148 makes contact with the stop140, the technician may close the hinge 110 such that the opening 112 ofhinge 110 fits over notch 114. Closing the hinge 110 allows the opticalfiber 148 to be secured in place along the flexible tongue 106.

The flexible tongue 106 is then bent and the tab 116 is snapped into theslot 120 of the body 102 of the bladeless cleaver 100 such that theflexible tongue 106 is locked into place. In the embodiment shown inFIGS. 15 and 16, the hinge 110 is used to hold the optical fiber 148against the fiber guide surface 107, and then a bending force at thedeformation 118 creates a separation to induce tension against a springin the spring fiber guide 138. The bending of the flexible tongue 106provides a bent radius for the portion 146 of the optic fiber 148 tofollow. In one embodiment, the radius provided by the bent flexibletongue 106 may be of radius R₅. R₅ may be equivalent to R₁ as discussedabove with respect to FIG. 4. The bend of radius R₅ in FIG. 16 places abend in the portion 146 of the optical fiber 148 prior to cleaving theoptical fiber 148. In one embodiment, the bent radius R₅ may be betweenapproximately three (3) and four (4) inches, although the bent radius R₅may be of any radius desired.

The bending of the flexible tongue 106 also applies the necessarytension to the portion 146 of the optical fiber 148 to be able tointroduce a flaw in the portion 146 of the optical fiber 148, which isnecessary to make a cleave of the optical fiber 148, as discussed above.After the tab 116 is snapped into the slot 120 of the body 102 of thebladeless cleaver 100 such that the flexible tongue 106 is locked intoplace, the bladeless cleaver 100 will appear as shown in FIG. 16.

With continuing reference to FIG. 16, once the portion 146 of theoptical fiber 148 has tension applied to it as a result of the bentflexible tongue 106, the technician can actuate the abrasive mediumcarrier 122 such that the abrasive medium carrier 122 is moved acrossthe portion 146 of the optical fiber 148 to induce the flaw in theportion 146 of the optical fiber 148. In one embodiment, the abrasivemedium carrier 122 may be controlled by human hand or a cleavingstructure, as discussed above, to place the abrasive medium 126 incontact with the portion 146 of the optical fiber 148 to induce the flawin the portion 146 of the optical fiber 148. The abrasive medium carrier122 may include an actuator 144 for actuating the abrasive mediumcarrier 122 such that the abrasive medium 126 is placed into contactwith the portion 146 of the optical fiber 148 bent around the flexibletongue 106 to induce a flaw in the portion 146 of the optical fiber 148.In one embodiment, the actuator 144 may be spring-actuated with thebladeless cleaver 100 in a manner similar to that illustrated in FIGS. 5and 6. The abrasive medium carrier 122 can be actuated to be moved in adirection D₅ towards the body 102 and fiber guide surface 107 byexerting a force on the actuator 144 towards the body 102. When theforce exerted on the actuator 144 is released, the abrasive mediumcarrier 122 is returned to its original position. When the abrasivemedium carrier 122 is moved towards the body 102, the abrasive mediumcarrier 122 places the abrasive medium 126 into contact with the portion146 of the optical fiber 148 bent around the flexible tongue 106 toinduce a flaw in the portion 146 of the optical fiber 148. The opticalfiber 148 is cleaved due to the bend and tension disposed in the opticalfiber 148 as a result of the flexible tongue 106 being bent and held inplace in the locked position shown in FIG. 16.

In the embodiment of FIG. 16, the optical fiber 148 is held in place bythe closed hinge 110 while the abrasive medium carrier 122 is moved in adirection D₅ towards the portion 146 of the optical fiber 148 bentaround the flexible tongue 106 to bring the abrasive medium 126 incontact with the portion 146 of the optical fiber 148. The abrasivemedium carrier 122 may be controlled in a swiping motion for example.The swiping motion may be in a linear motion in the direction D₅, or theswiping motion may follow an arcuate path. Once the flaw is created, thetension and bend provided by the bent flexible tongue 106 will propagatethe cleave through the optical fiber 148 creating a usable end face.

When the cleave is made, the portion 146 of the optical fiber 148 to beused may be removed from the bladeless cleaver 100. A scrap portion 147of the optical fiber 148 will remain held in place by the hinge 110. Thescrap portion 147 may then be removed from the bladeless cleaver 100 bythe technician opening the hinge 110 and the scrap portion 147 can bediscarded. Alternatively, if the bladeless cleaver 100 is designed as asingle use cleaver or a disposable cleaver whose recommended number ofuses has been reached, the entire bladeless cleaver 100 with theretained scrap portion 147 may be thrown away. In one embodiment, wherethe abrasive medium 126 is provided in the form of tear away sheets offilm, the body 102 of the bladeless cleaver 100 may be used multipletimes, with the sheets of film being torn away after each use by openingthe cover portion 124 of the abrasive medium carrier 122.

The abrasive medium 126 may be similar to the abrasive medium 20disclosed above with respect to FIG. 1. For example, the abrasive medium126 may be material provided in grit form on the abrasive medium carrier122. The abrasive medium 126 may be provided by any type of material orcombination or compound of elements or materials. Non-limiting examplesof the abrasive medium 126 include, but are not limited to diamond,silicon carbide, aluminum oxide, silicon dioxide, cerium oxide, andferrous oxide. The size of the abrasive medium 126 may be any size. Asan example only, the size of the abrasive medium 126 may be between five(5) and twenty (20) micrometers (μm) as a non-limiting example. Forexample, the abrasive medium 126 may be fifteen (15) μm diamond, oreight (8) μm carbide, as non-limiting examples.

In addition, the abrasive medium 126 may be in the form of tear awaysheets of film in one embodiment. The film may be a polishing film as anexample. In the embodiment of FIG. 15, the tear away sheets are held inplace by abrasive medium holding members 128A and 128B. The abrasivemedium 126 may be disposed or deposited on the entire surface area ofthe film or only a portion of the surface area of the film. For example,the abrasive medium 126 may be disposed on an edge of the film.

In addition, the abrasive medium carrier 122 may be rigid or flexible.Providing a flexible abrasive medium carrier 122 allows a preciseportion of the abrasive medium 126 disposed or deposited thereon to beplaced into contact with the portion 146 of the optical fiber 148 toinduce the flaw. Providing a flexible abrasive medium carrier 122 mayalso allow the deploying of the abrasive medium 126 in cleavers andother packagings that may not be possible or convenient if aconventional blade cleaver were employed. The abrasive medium 126 doesnot include a conventional sharp blade that can easily be placed intoprecise contact with an optical fiber.

In the embodiments where the abrasive medium 126 is disposed on sheetsof film, the attachment of the film may be of low tolerance. Inaddition, the film comprising the abrasive medium 126 may be configuredsuch that the film has a slight bow to it, which will translate into adownward force against the portion 146 (with exposed glass) of theoptical fiber 148 during cleaving. The amount of the bow in oneembodiment is enough to ensure that the film having the abrasive medium126 is in contact with the portion 146 (with exposed glass) of theoptical fiber 148 during as much of the swiping motion of the abrasivemedium carrier 122 as possible. In this manner, the flexible film willallow the abrasive medium 126 to remain in contact with the portion 146(with exposed glass) of the optical fiber 148 without having to maintainhigh tolerances for the location of the film.

Other non-limiting examples of carriers for the abrasive medium 126include, but are not limited to, a wire, a string, a block, and a body.The abrasive medium carrier 122 may be of any size and made from anytype of material desired, including but not limited to a polymer,plastic, and metal, as non-limiting examples. The quality and nature ofthe abrasive medium 126 and the abrasive medium carrier 122 determinethe life or number of uses to cleave the optical fiber.

The bladeless cleaver 100 as shown in FIGS. 15 and 16 may be designed asa single (or low use) cleaver to be used in a cost effective way. Thebladeless cleaver 100 may be shipped as a consumable with the otherparts, such as connectors, used by a technician to establish an opticalconnection in the field. In this manner, cleaver maintenance may beeliminated as the cleaver will simply be disposed of after its life isused up. In addition, because of the use of a flexible abrasive mediumcarrier, the components of the cleaver may have simpler designs with lowprecision molded components. This low precision should allow for thecomponents to be manufactured inexpensively and any necessary assemblywill not require critical alignment. In one embodiment, the body of thebladeless cleaver 100 may be an inexpensive plastic component thatallows for a flexible tongue 106 to be molded into it. In addition, theuse of the hinge 110, particular in the form of living hinges, willallow for the entire assembly to be molded which will keep thecomponents cheap. However, although the embodiment of FIGS. 15 and 16includes a hinge 110 to hold the optical fiber 148 in place during thecleaving process, such a hinge 110 is not required. For example, theoptical fiber could be held in place by an adhesive provided on thefiber guide surface 107 of the flexible tongue 106, or the optical fiber148 could even be held in place by the technician during the inductionof the bend.

The embodiments disclosed herein are not limited to any particularoptical fiber, abrasive medium, carrier, angle of cleaving, stress, andfiber stripping, and method of applying the abrasive medium to theoptical fiber. The cleaved optical fiber ends disclosed herein may bedisposed or formed on individual fibers or arrays of fibers. A polishingprocess may be performed after the optical fiber is cleaved.

As used herein, it is intended that terms “fiber optic cables” and/or“optical fibers” include all types of single mode and multi-mode lightwaveguides, including one or more bare optical fibers, loose-tubeoptical fibers, tight-buffered optical fibers, ribbonized opticalfibers, bend-insensitive optical fibers, or any other expedient of amedium for transmitting light signals. An example of a bend-insensitive,or bend resistant, optical fiber is ClearCurve® Multimode fibercommercially available from Corning Incorporated. Suitable fibers ofthis type are disclosed, for example, in U.S. Patent ApplicationPublication Nos. 2008/0166094 and 2009/0169163.

Bend insensitive multimode optical fibers may comprise a graded-indexcore region and a cladding region surrounding and directly adjacent tothe core region, the cladding region comprising a depressed-indexannular portion comprising a depressed relative refractive indexrelative to another portion of the cladding. The depressed-index annularportion of the cladding is preferably spaced apart from the core.Preferably, the refractive index profile of the core has a parabolic orsubstantially curved shape. The depressed-index annular portion may, forexample, comprise a) glass comprising a plurality of voids, or b) glassdoped with one or more downdopants such as fluorine, boron, individuallyor mixtures thereof. The depressed-index annular portion may have arefractive index delta less than about −0.2% and a width of at leastabout one (1) μm (micron), said depressed-index annular portion beingspaced from said core by at least about 0.5 microns.

In some embodiments that comprise a cladding with voids, the voids insome preferred embodiments are non-periodically located within thedepressed-index annular portion. By “non-periodically located” we meanthat when one takes a cross section (such as a cross sectionperpendicular to the longitudinal axis) of the optical fiber, thenon-periodically disposed voids are randomly or non-periodicallydistributed across a portion of the fiber (e.g. within thedepressed-index annular region). Similar cross sections taken atdifferent points along the length of the fiber will reveal differentrandomly distributed cross-sectional hole patterns, i.e., various crosssections will have different hole patterns, wherein the distributions ofvoids and sizes of voids do not exactly match for each such crosssection. That is, the voids are non-periodic, i.e., they are notperiodically disposed within the fiber structure. These voids arestretched (elongated) along the length (i.e. generally parallel to thelongitudinal axis) of the optical fiber, but do not extend the entirelength of the entire fiber for typical lengths of transmission fiber. Itis believed that the voids extend along the length of the fiber adistance less than about 20 meters, more preferably less than about ten(10) meters, even more preferably less than about 5 meters, and in someembodiments less than one (1) meter.

The multimode optical fiber disclosed herein exhibits very low bendinduced attenuation, in particular very low macrobending inducedattenuation. In some embodiments, high bandwidth is provided by lowmaximum relative refractive index in the core, and low bend losses arealso provided. Consequently, the multimode optical fiber may comprise agraded index glass core; and an inner cladding surrounding and incontact with the core, and a second cladding comprising adepressed-index annular portion surrounding the inner cladding, saiddepressed-index annular portion having a refractive index delta lessthan about −0.2% and a width of at least one (1) micron, wherein thewidth of said inner cladding is at least about 0.5 microns and the fiberfurther exhibits a one (1) turn, ten (10) millimeters (mm) diametermandrel wrap attenuation increase of less than or equal to about 0.4decibel (dB)/turn at 850 namometers (nm), a numerical aperture ofgreater than 0.14, more preferably greater than 0.17, even morepreferably greater than 0.18, and most preferably greater than 0.185,and an overfilled bandwidth greater than 1.5 GigaHertz (GHz)-kilometer(km) at 850 nm.

Fifty (50) micron diameter core multimode fibers can be made whichprovide (a) an overfilled (OFL) bandwidth of greater than 1.5 GHz-km,more preferably greater than 2.0 GHz-km, even more preferably greaterthan 3.0 GHz-km, and most preferably greater than 4.0 GHz-km at an 850nm wavelength. These high bandwidths can be achieved while stillmaintaining a one (1) turn, ten (10) mm diameter mandrel wrapattenuation increase at an 850 nm wavelength of less than 0.5 dB, morepreferably less than 0.3 dB, even more preferably less than 0.2 dB, andmost preferably less than 0.15 dB. These high bandwidths can also beachieved while also maintaining a 1 turn, 20 mm diameter mandrel wrapattenuation increase at an 850 nm wavelength of less than 0.2 dB, morepreferably less than 0.1 dB, and most preferably less than 0.05 dB, anda 1 turn, 15 mm diameter mandrel wrap attenuation increase at an 850 nmwavelength, of less than 0.2 dB, preferably less than 0.1 dB, and morepreferably less than 0.05 dB. Such fibers are further capable ofproviding a numerical aperture (NA) greater than 0.17, more preferablygreater than 0.18, and most preferably greater than 0.185. Such fibersare further simultaneously capable of exhibiting an OFL bandwidth at1300 nm which is greater than about 500 MHz-km, more preferably greaterthan about 600 MHz-km, even more preferably greater than about 700MHz-km. Such fibers are further simultaneously capable of exhibitingminimum calculated effective modal bandwidth (Min EMBc) bandwidth ofgreater than about 1.5 MHz-km, more preferably greater than about 1.8MHz-km and most preferably greater than about 2.0 MHz-km at 850 nm.

Preferably, the multimode optical fiber disclosed herein exhibits aspectral attenuation of less than 3 dB/km at 850 nm, preferably lessthan 2.5 dB/km at 850 nm, even more preferably less than 2.4 dB/km at850 nm and still more preferably less than 2.3 dB/km at 850 nm.Preferably, the multimode optical fiber disclosed herein exhibits aspectral attenuation of less than 1.0 dB/km at 1300 nm, preferably lessthan 0.8 dB/km at 1300 nm, even more preferably less than 0.6 dB/km at1300 nm.

In some embodiments, the numerical aperture (“NA”) of the optical fiberis preferably less than 0.23 and greater than 0.17, more preferablygreater than 0.18, and most preferably less than 0.215 and greater than0.185.

In some embodiments, the core extends radially outwardly from thecenterline to a radius R, wherein 10≦R≦40 microns, more preferably20≦R≦40 microns. In some embodiments, 22≦R≦34 microns. In some preferredembodiments, the outer radius of the core is between about 22 to 28microns. In some other preferred embodiments, the outer radius of thecore is between about 28 to 34 microns.

In some embodiments, the core has a maximum relative refractive index,less than or equal to 1.2% and greater than 0.5%, more preferablygreater than 0.8%. In other embodiments, the core has a maximum relativerefractive index, less than or equal to 1.1% and greater than 0.9%.

In some embodiments, the optical fiber exhibits a one (1) turn, ten (10)mm diameter mandrel attenuation increase of no more than 1.0 dB,preferably no more than 0.6 dB, more preferably no more than 0.4 dB,even more preferably no more than 0.2 dB, and still more preferably nomore than 0.1 dB, at all wavelengths between 800 and 1400 nm.

FIG. 17 shows a schematic representation of the refractive index profileof a cross-section of the glass portion of an embodiment of a multimodeoptical fiber 200 comprising a glass core 202 and a glass cladding 204,the cladding comprising an inner annular portion 206, a depressed-indexannular portion 208, and an outer annular portion 210. FIG. 18 is aschematic representation (not to scale) of a cross-sectional view of theoptical waveguide fiber of FIG. 17. The core 202 has outer radius R₂ andmaximum refractive index delta Δ1MAX. The inner annular portion 206 haswidth W₁ and outer radius R₃. Depressed-index annular portion 208 hasminimum refractive index delta percent Δ3MIN, width W₂ and outer radiusR₄. The depressed-index annular portion 208 is shown offset, or spacedaway, from the core 102 by the inner annular portion 206. The annularportion 208 surrounds and contacts the inner annular portion 206. Theouter annular portion 210 surrounds and contacts the annular portion206. The clad layer 204 is surrounded by at least one coating 212, whichmay in some embodiments comprise a low modulus primary coating and ahigh modulus secondary coating.

The inner annular portion 206 has a refractive index profile Δ2(r) witha maximum relative refractive index Δ2MAX, and a minimum relativerefractive index Δ2MIN, where in some embodiments Δ2MAX=Δ2MIN. Thedepressed-index annular portion 208 has a refractive index profile Δ3(r)with a minimum relative refractive index Δ3MIN. The outer annularportion 210 has a refractive index profile Δ4(r) with a maximum relativerefractive index Δ4MAX, and a minimum relative refractive index Δ4MIN,where in some embodiments Δ4MAX=Δ4MIN. Preferably, Δ1MAX>Δ2MAX>Δ3MIN. Insome embodiments, the inner annular portion 206 has a substantiallyconstant refractive index profile, as shown in FIG. 17 with a constantΔ2(r); in some of these embodiments, Δ2(r)=0%. In some embodiments, theouter annular portion 210 has a substantially constant refractive indexprofile, as shown in FIG. 17 with a constant Δ4(r); in some of theseembodiments, Δ4(r)=0%. The core 202 has an entirely positive refractiveindex profile, where Δ1(r)>0%. R1 is defined as the radius at which therefractive index delta of the core first reaches value of 0.05%, goingradially outwardly from the centerline. Preferably, the core 202contains substantially no fluorine, and more preferably the core 202contains no fluorine. In some embodiments, the inner annular portion 206preferably has a relative refractive index profile Δ2(r) having amaximum absolute magnitude less than 0.05%, and Δ2MAX<0.05% andΔ2MIN>−0.05%, and the depressed-index annular portion 208 begins wherethe relative refractive index of the cladding first reaches a value ofless than −0.05%, going radially outwardly from the centerline. In someembodiments, the outer annular portion 210 has a relative refractiveindex profile Δ4(r) having a maximum absolute magnitude less than 0.05%,and Δ4MAX<0.05% and Δ4MIN>−0.05%, and the depressed-index annularportion 208 ends where the relative refractive index of the claddingfirst reaches a value of greater than −0.05%, going radially outwardlyfrom the radius where Δ3MIN is found.

Many modifications and other embodiments set forth herein will come tomind to one skilled in the art to which the embodiments pertain havingthe benefit of the teachings presented in the foregoing descriptions andthe associated drawings. Therefore, it is to be understood that thedescription and claims are not to be limited to the specific embodimentsdisclosed and that modifications and other embodiments are intended tobe included within the scope of the appended claims. It is intended thatthe embodiments cover the modifications and variations of theembodiments provided they come within the scope of the appended claimsand their equivalents. Although specific terms are employed herein, theyare used in a generic and descriptive sense only and not for purposes oflimitation.

What is claimed is:
 1. A bladeless cleaver for cleaving an opticalfiber, comprising: a body having a flexible tongue that is manuallyconfigurable to provide an arcuate surface having an adjustable radius,the flexible tongue configured to receive a portion of an optical fiberand provide the arcuate surface to directly contact and bend the portionof the optical fiber; and a cleaver structure attached to the body andcomprising an abrasive medium carrier configured to support an abrasivemedium, wherein the abrasive medium does not include a sharp edge,wherein the abrasive medium carrier is configured to be actuated toplace the abrasive medium in contact with the portion of the opticalfiber to create a flaw in the portion of the optical fiber.
 2. Thebladeless cleaver of claim 1, wherein the flexible tongue furthercomprises a hinge for holding the optical fiber against the arcuatesurface provided by the flexible tongue.
 3. The bladeless cleaver ofclaim 2, wherein the hinge is a living hinge.
 4. The bladeless cleaverof claim 1, wherein the abrasive medium is disposed on the abrasivemedium carrier in sizes between 5 micrometers (μm) and 50 micrometers(μm).
 5. The bladeless cleaver of claim 1, wherein the abrasive mediumcarrier is comprised from the group consisting of a film, a wire, astring, a block, and a body.
 6. The bladeless cleaver of claim 1,wherein the arcuate surface has a non-uniform radius.
 7. The bladelesscleaver of claim 6, wherein the radius is between three (3) and four (4)inches.
 8. The bladeless cleaver of claim 1, wherein the flexible tongueincludes a deformation at which a portion of the flexible tongue canbend.
 9. The bladeless cleaver of claim 1, wherein the flexible tongueis detachable from the body.
 10. A bladeless cleaver for cleaving anoptical fiber, comprising: a body having a flexible tongue extendedcantilever from the body, wherein the flexible tongue receives a portionof an optical fiber and provides an arcuate surface along which to bendthe portion of the optical fiber; and a cleaver structure attached tothe body and comprising an abrasive medium carrier and an abrasivemedium attached to the abrasive medium carrier, wherein the abrasivemedium does not include a sharp edge, wherein the abrasive mediumcarrier is actuated to place the abrasive medium in contact with theportion of the optical fiber to create a flaw in the portion of theoptical fiber.